Electron emission control tube and method



Nov. 1, 1966 J. E. M GRlFF ELECTRON EMISSION CONTROL wuss AND METHOD Original Filed April 22. 1960 Mm 1 o M t T6 4. I e N a m Tm r, s m 7 W 5 W4 K c a m M Nov. 1, 1966 J. E. M GRlFF ELECTRON EMISSION CONTROL TUBE AND METHOD Original Filed April 22, 1960 5 Sheets-Sheet 2 BY dia firm. I M

Arr-menial Nov. 1, 1966 J. E. M GRIFF 3,233,069

ELECTRON EMISSION CONTROL TUBE AND METHOD Original Filed April 22, 1960 5 Sheets-Sheet :5

INVENTOR. E Mac GP/Fp ArraRA/EY United States Patent 3,283,069 ELECTRON EMISSION CONTROL TUBE AND METHOD Jack E. MacGritf, 17205 Lahser Road, Detroit, Mich. Original application Apr. 22, 1960, Ser. No. 24,168, now

Patent No. 3,242,261, dated Mar. 22, 1966. Divided and this application Feb. 9, 1966, Ser. No. 526,306

25 Claims. (Cl. 1786.6)

This application is a division of my copending application Serial No. 24,168, filed April 22, 1960, now Patent No. 3,242,261, relating to an electron Emission Control Tube and Method of Printing, which was a continuationin-part of my application Serial No. 607,446, filed August 31, 1956, now Patent No. 2,934,673, and application Serial No. 623,152 filed November 19, 1956, now abandoned.

The difficulty with image control tubes such as Kernkamp Patent No. 2,291,476 and other, is that they are mechanically impossible to construct with close spacing of the end-face conductors; they are not designed for electron emission from the ends of the target conductors across a space; the trace of the electron beam is not visible during operation, and focusing and alignment of the beam across the conductors is diflicult and can not be done unless the response of the individual conductor to the electron beam, as it is swept past the target row, is measured.

Kernkamp, for example, has flat, arrow-shaped conductors that are, at their smallest tips, 0.015 inch square. Assuming a spacing between conductors equal to the width of the conductor, this would mean only 33 conductors per lineal inch of image.

Kernkamp, as is common with most recorded references in the art, discloses no method of making these conductors extremely close together; for example, 500 per lineal inch, nor does Kernkamp describe a method of focusing or aligning the beam trace with the row of conductors, other than distorting the electron beam from its normal circular cross section.

This problem is further made difiicult because the interior ends of the conductors are not flush with the interior end face of the tube, but extend into the tube from the end wall. If a small diameter spot electron beam is used with a close conductor spacing, the diameter of the beam as it contacts each conductor the same size as the conductor itself, for example, 0.001 inch or smaller in diameter, a very small misalignment sometimes prohibits the tube from operating correctly because the beam does not properly contact the individual conductors.

The purpose of this invention is to overcome these difficulties and provide a novel method of construction of an electron emission control cathode ray tube, which permits an extremely close conductor spacing, with provision for visible view of the electron beam trace at all times, with simple alignment of the electron beam trace, and to further provide a means to control the formation of two or more separate and distinct external images at the same time, and further to provide a means for supplying more than one cathode ray beam to each emission conductor at the same time, and further to provide a new and novel method of operation.

The cathode ray tube described in this invention can be used with a single electron gun or with a multiplicity of electron guns.

These and other objects will be seen from the following specification and. claims in conjunction with the appended drawings in which:

FIG. 1 is a fragmentary, partially broken away, perspective view of one form of the present emission control tube.

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FIG. 2 is a schematic plan view of the present emission control tube as used for the simultaneous forming or printing of images.

FIG. 3 is a diagrammatic illustration illustrating a different method of operation employing a multiple tube system to form a large image.

FIG. 4 is a fragmentary plan view thereof.

FIG. 5 is a diagrammatic view illustrating said multiple tube system for forming images upon a movable web.

FIG. 6 is a fragmentary side elevational view illustrating the respective positioning of the pair of rows of image tubes in FIG. 5, on an increased scale.

FIG. 7 is a fragmentary side elevational view of an insulating plate having a row of emission conductors wider than in a single cathode ray tube, with a plurality of such tubes in contact therewith for transmitting signals to the respective plate conductors.

FIG. 8 is a fragmentary plan view thereof with dotted lines indicating the positioning of said tubes.

FIG. 9 is a fragmentary side elevational view of an emission control tube having a multi-layer end face with each layer having a series of emission conductors.

FIGS. 9A, 9B, and 9C are fragmentary side elevational views similar to FIG. 9 showing slightly different forms of multiple layer tube end faces.

FIG. 10 is a schematic side elevational view of a similar tube on an enlarged scale with plural end faces.

FIG. 11 is a fragmentary perspective view of the tube shown in FIG. 9, partially broken away for illustration, and on an increased scale.

FIGS. 12 and 13, fragmentarily illustrate a control tube having multiple layer circular tube end faces.

FIG. 14 is another form of such tube.

FIG. 15 fragmentarily illustrates another form of multiple end face plate tube assembly.

It will be understood that the above drawings illustrate merely several preferred embodiments of the invention and that other embodiments are contemplated within the scope of the claims hereafter set forth:

In one simple envisioned embodiment of the invention, as in FIG. 1, and shown in cross section in FIG. 2, in a cathode ray tube 11' there are a plurality of electron guns and control elements, each containing an electron emission source 35, connected by lead 36 to power line 37, a beam forming electrode 35, a control grid 38, and accelerating anode 39; and. internal or external beam focusing and deflection systems 3-4.

The multiplicity of electron emission and control guns are positioned at one end of a cathode ray tube, and a target plate of conductors 8 is positioned at the other end of the evacuated tube, wtih conductors 14 affixed thereto and the assembly substantially perpendicular to the longitudinal axis of the tube. This plate is therefore substantially perpendicular to the direction of travel of the undeiiected electron beams 11. Target plate 8 consists of a support plate of insulating material, such as glass, to which are afiixed a series of coplanar closely spaced, (such as 500 per inch) elongated conductors 14 in insulated position on said plate. This plate can also be the end-face of the cathode ray tube, with the conductors on the interior surface, said conductors extending across the end face plate in such a manner that the ends of the conductors are external to the tube, while a substantial portion of their lengths are on the interior surface substantially perpendicular to the longitudinal axis of the tube.

Insulating plate 8 with conductors 14 afiixed, substantially perpendicular to the longitudinal axis of the undeflected electron beam, can be of any shape, and is not limited to the standard end face shape-s normally used in cathode ray tubes. For example, the end face can be circular, square, rectangular, triangular, polygonal, or

even shaped like an O, or donut-shaped, with a circular hole in the center. Many other forms can be used. Conductors aflixed to this end plate do not necessarily have to be straight, or extend completely across the glass plate. Neither do they have to be parallel.

Depending on the number of external images desired, or other use to which an electron emission control tube can be put, the pattern of the conductors on the glass plate can take many forms.

FIG. 1 shows a rectangular glass plate 8 with a series of straight, parallel, coplanar closely spaced elongated conductors 14 afiixed in insulated position tosaid plate and arranged in a row, the respective ends of said conductors terminating at the respective edges of said glass plate.

It is substantially identical to the plate with conductors aifixed as used in my U.S. Patent No. 2,771,336, and U.S. Patent No. 2,934,673,

When I speak of images being formed, I am referring to the processes described in my U.S. Patent No. 2,771,- 336.

It may be desired to have a row of emission conductors wider than possible to prepare in any single cathode ray tube.

FIGS. 5, 6, 7, and 8 show such a system.

In FIG. 3, a revolving drum 23 illuminated at 24 with the image to be reproduced is set up in front of a lens 25, image-splitting mirror 26 and two rows of image pick-up tubes, such as oconoscopes or image orthicons, etc., at 27 and 28. A top view of this is shown in FIG. 4. The tubes are so staggered and arranged that portions from the various image areas designed 12-3-456-7etc., are focused on particular pickup tubes such as 27a, 27c, FIG. 4, or the other tubes numbered 1, 3, 5, and 7, with every second tube being in the second row. Signals from these tubes are fed to separate sets of image tubes 30 and 31 such as in FIG. at 1-2-3-4-5-6-7. As the image receiving web 29 passes the image tubes, by a suitable pigment deposition system, (see my Patent No. 2,771,336) or by using electro-sensitive paper, for example, the en tire image is reproduced.

Each of the sets of tubes 30 and 31 correspond to the tube 1 above described with respect to FIG. 1 in U.S. Patent No. 2,934,673. The spacing between X-Y is equal to one image length, so that in one image length, the

tube-image-traces match up on the receiving web and form a complete image. The various signals from the signal tubes 27, 28 can be properly positioned on the image deposition tubes 30-31 by proper width and center ing controls, as is standard in the electronic art.

The signal images can be recorded on magnetic tape, and fed to the image producing tubes 30, 31 in a similar manner.

An additional advantage in the use of such small tubes is that with this system we can obtain an image resolution of 500 to 600 lines per linear inch of image regardless of image size; and this is extremely important. Such a construction also cuts down the frequency or maximum frequencies necessary to pass through the signal amplifier.

An image, which is represented here by the exterior of drum 23, in FIG. 4, is scanned by a series of iconoscopes shown in FIGS. 3 and 4 as at 27A, 27B, 27C, 28 (13-57).

Light from the source is reflected from a master image on the drum through a lens 25 and a prism 26, which splits the image into two parts.

Part of it goes to i-cono-scopes 2 and 4-6 and part to iconoscopes 1, 3, 5 and 7, as shown.

Each iconoscope receives a portion of the image as designated by parts 1-7 on drum 23 in FIG. 4.

As each iconoscope scans only its small part of the image, that portion of the total image signal is passed on 4 to an image control electron emission tube, as shown in FIG. 5.

A series of tubes are placed as shown at 30 and 31, and extending across the width of web 29. The distance between the emission conductors of tubes 30 and 31 is equal to the circumference of the drum 23 or one complete image.

As shown in FIG. 5, the image from tube 1 and the image from tube 3 are formed in the same line, but the image from tube 4 is formed at a later position, but synchronized with the other images so that the complete image is blended. Any number of tubes can be used in this manner for as wide an image as desired.

Another system for forming the image at one spot but using a multiplicity of tubes is shown in FIG. 7 and FIG. 8. Here, an external insulating plate with conductors 99 is formed. But the plate here is wider than the tubes themselves, and the image tubes can be positioned as at 101, 102, 103 in FIG. 7, and shown in FIG. 8. Any number of tubes can be positioned in this manner, to give as Wide a unit as desired.

The image control tubes can be positioned as at 101A and as image tube 103, so that two images can be fed to the same spot to super-impose information, such as would be done with a photo :printed through two negatives on top of one another.

The emission ends of the conductors on the external glass plate are then used as would be the emission conductors from the tube itself, except that in this case the row of conductors is much wider.

Multislayer tube end faces can be used, as shown in FIGS. 9, 9A, 9B, 9C, 10, 11, l2, l3, l4 and 15.

FIG. 9 shows tube 108 with stacked rectangular end face plates 109, 110, .111, 112, and as is used in the tube of FIG. 1. Each plate has the same width, but is longer than the one preceding it, hence has longer conductors 14.

These can be several glass, mica, or other insulating media plates, formed in a regular manner, as previously described, with the first end plate 109, with conductors 14, being of suitable thickness to withstand the vacuum of the tube, and the subsequent layers on thin glass-for example, 0.0l0 inch or thinner.

Another manner of preparation is to form the first layer of conductors 14 on the thick plate 109, which may be the end face of the tube; coat the glass plate and conductors with an insulating material such as a low-temperature glass frit in a very thin layer, over the portion of the end plate where the second layer of conductors is to be formed, fuse the insulating material over the portion of the end plate to which the next layer of conductors will be atfixed; forming a second layer of conductors by vacuum coating and photo-etching, etc., and continuing the process for as many layers as desired. Each succeeding layer of insulating material, if it is of the type that must be fused by heat, must be of a correspondingly lower melting point than the previous layer. In this manner, many layers of conductors can be formed very close together. Each layer, of course, does not extend as far into the tube as the previous one, so that a substantial portion of each conductor is still uncovered by the next layer, so that each individual conductor is exposed to the electron beam or beams.

If the conductors are formed on individual layers of glass, mica, etc, the layers can be fused together with the same low-temperature glass such as Corning No. 7570 as used to seal the end plate to the cathode ray tube itself.

When multi-plate end faces are used, as in FIG. 9, the plates and conductors can be at a small angle to the undeflected electron beam axis, as in FIG. 10, so that the spot of each conductor contacted by the electron beam is in the same plane, which plane C-C is substantially perpendicular to the tube axis and hence the undellected electron beam of the tube itslef. Similarly a line connecting a spot on each conductor which can be contacted by the electron beam can form an arc, the center of which is at the electron gun assembly.

The shape of the exterior surface of such a multi-layer end face cathode ray tube depends on the manner in which it is used, and the ends of the conductors can be flush, FIG. 9, 9A, and 10; tapered, FIG. 9B; or staggered, FIG. 9C, for example.

Other exterior configurations can be used, as arcuate in FIG. adjacent web 29 movable over drum 29'.

All of the design considerations of the single layer end face tubes, as heretofore and hereafter described, apply to the multi-layer end face tubes, such as interior coatings, fluorescent layers, secondary emission control fields and wires, multiple electron guns, and ionization bias prechnrge sources, hereafter described, for example.

The rnulti-layer end face plates do not have to be rectangular, but can be circular, or any other shape. Circular plates 113, 114, 115 are shown in FIGS. 12 and 13, for example. When the end face is multi-layer type, the fluorescent layer is only applied to the portion of conductors l4 and plate exposed to the electron beam or beams, and not between the layers of insulating material. The fluorescent layer can be applied after the layers are sealed together, for example.

FIG. 14 shows a circular end face tube 116 with the conductors 14 at a slight angle to the tube axis, so that the portion of the conductors contacted by the electron beam are in a plan substantially perpendicular to the tube axis itself. In this case, the end face plate 117 is conical with the other layers of insulating material and conductors formed on the conical base.

There are many advantages of operation of this design and type of electron emission control tube over the patents of record. One method, for example, using a single layer end face tube with parallel conductors substantially perpendicular to the axis of the undeflected electron beam, with end face conductors 14 as shown in FIGS. 1 and 2.

Several methods of operation, as described in my US. Patent No. 2,771,336, and patent application 623,152, are shown in FIG. 2.

Since an electron emission control tube of this type can form more than one image at once, two image control stations are shown.

In operation, external accelerating electrodes 32 and 32' are positioned as shown in FIG. 2, external to the tube surfac eand spaced therefrom, but parallel to the emission ends of the end face conductors 14.

The electron beam 11 is swept across the parallel conductors by a saw-tooth signal, for example, as described in my U.S. Patent No. 2,771,331 and my US. Patent No.

2,934,673, and patent application 623,152 filed November 19, 1965.

The methods of operation as described in my Patent No. 2,771,336 and appliaction 623,152 also apply to this tube, except that two complete separate and distinct images are simultaneously formed at two stations, as shown in FIG. 2. The two images thus formed do not have to be formed by the same method.

Briefly, the electron beam 11 is swept in contact with each conductor 14 in sequence, and modulated by an external signal 54' applied at 26 to the control grid 38 of the electron gun.

As the electrons in the beam contact each conductor 14, they are conducted transversely to the exterior of the tube, through the side wall, and escape the external ends of the conductors and travel through space, for example, 0.001 inch, in the direction of the external acceleration electrodes 32-32. This acceleration electrode may be a metallic knife-blade, or comb design, as is shown in references cited as patents issued and applications filed by myself, or can be parallel conductors 45 formed on an insulating glass plate 44, as shown in FIGURE 1, and interconnected.

The exterior accelerating electrode is described in my Patent No. 2,771,336, and Patent No. 2,934,673. It can be a series of parallel conductors aflixed to a glass plate 44 or other insulating material, with the spacing the same as the spacing of the conductors 14 in the end face plate 8 of the electron emission control tube, with all of the conductors 45 connected at 118 at one edge of the plate and the unconnected ends of the conductors 45 parallel to and opposite the external emission ends of the tube end face conductors 14.

When the image control electron emission tube is used with a smoke-mist generator system as described in my Patent N0. 2,771,336, and also shown in FIG. 2, the electrons travel through a smokemist pigment 36', to a movable image receiving Web 28', which is positioned between the external electrode 32, and the conductor ends, and spaced, for example, approximately .002 inch from the external emission ends of the tube conductors. Particles of pigment 36' are deposited on and in the image web in proportion to the image signal 54' applied to the electron gun modulating grid 38 of the cathode ray tube.

Other types of operation can consist, for example, of forming invisible electrostatic images on movable webs, or rotating drums, with subsequent use, or said electrostatic image being remotely made visible, or transferred to another media, as described in the two aforementioned patent applications, or other processes well known to those versed in the art.

If the smoke-mist pigment generator 34, the housing 34, the blower 35", and the smokemist pigment 36' are removed, the operation is as follows:

When the tube is in operation, the high voltage electron (600-5000 volts, for illustration) beam 11 is caused to scan the row of conductors 14 by the deflection system, and by varying the intensity of the scanning field, the electron beam 11 will be so deflected as to intermittently scan the row of conductors 14 starting with conductor at extreme left in FIG. 1, and ending with the conductor, for example, on extreme right.

The electron beam scans this row of conductors during a slow moving deflection field, and returns to the start of the scan during a rapid-retrace or flyback signal in the conventional manner.

As shown in FIG. 2, the web 28' is adapted to move past the end face of the tube. The image signal designated by the numeral 54 is fed to the control grid 38 of the electron gun assembly by the lead wire 26. The high voltage electron beam is emitted from the cathode in the quantity allowed by the instantaneous image signal on the control grid. The electron beam 11 passes through the scanning field and strikes one conductor 14. passes through the conductor and through the side of the tube, and then passes through a space, in the direction of the external accelerating electrode 32, inside the rotating drum 29', with the circuit completed through lead 33'.

As the electron beam 11 passes to the web 28, an electrostatic charge is impressed thereon. Thus, with the beam successively scanning the conductors 14 from one end to the other of the row. an electrostatic charge or image will be impressed on the web 28' in a row corresponding to the emission ends of the row of conductors 14. Thus, as the web 28' of paper or plastic material or other material move-s, electrostatic image lines will be formed across said web corresponding to the intensity of electrons passed by the control grid of the electron gun. Therefore, it follows that the electrostatic image on the web is controlled by the instantaneous signal 54 directed to the gun assembly through the lead 26 as shown in FIG. 2.

The high voltage electrode 32' can be operated at a higher potential than the accelerating anode 39. The instantaneous and varying potential of the grid 38 as regulated by the image signal 54' thus control the deposition of an electrostatic charge or image upon the web 28' in a row corresponding to the emission ends of the row of spaced conductors 14.

For detailed operation of the tube with the smoke-mist pigment system, refer to my Patent No. 2,771,336.

The other image forming station of FIG. 2 can be another process completely described in my application 623,152. At this station, for example, the electrostatic image is formed directly on a drum 59, and subsequently made visible by pigment at station 61, and transferred to the image web 28 extending around rolls 60-60 by the high voltage fields set up by high voltage discharge grid 63 and receiving anode 63'.

Said image is subsequently fused to the web at the station 62 and 62', and the drum cleaned by the rotating brush 65 and vacuum system 66.

Another method of operation is to constantly charge the drum with an evenly distributed electrostatic field with a high voltage charging apparatus at 64 and 64', and the emission from the conductors 14 counteracting this charge.

Another method of operation is to form an evenly dis tributed electrostatic charge on the surface of the drum 59 by the high voltage charging apparatus 64 and 64' with the electrons emitted from the emission ends of the conductors 14 which travel across space in the direction of the high voltage accelerating electrode 32, depending upon the image signal 54' fed to the electron gun that emits the beam 11, said electrons variously not affecting the charge, dissipating the charge partially, dissipating the charge completely, or dissipating the charge and being in such excess that they form a charge of the opposite polarity in varying amounts on the surface of the drum.

Thus, after the rotatable drum surface passes the emission ends of the conductors 14, the charge on the surface could be the original charge, no charge at all], or the opposite polarity charge, in varying amounts.

All of these image deposition systems are described in my Patent No. 2,771,336, and Patent No. 2,934,673.

Such systems include having the electrostatic charge formed on the web 28' being subsequently made visible at station 67 and made permanent at station 68, among other methods.

When :used with a smoke-mist generator system, as described in Patent No. 2,771,336, briefly the electrons travel through the smoke-mist pigment 36' to the movable image receiving web 28', which is positioned between the external electrode 32' and the emission ends of the conductors 14, and spaced from the external emission ends of the conductors.

Particles of pigment are deposited on and in the image web in proportion to the image signal applied to the electron gun modulating grid 38 in the cathode ray tube.

Because of the length of each conductor 14 exposed to the interior of the tube, substantially penpendicular to the longitudinal axis of the tube, the electrons from more than one electron gun, FIG. 2, can be simultaneously swept past the row of end face conductors without interaction or interference, with the traces of each beam simultaneously visible. Multiple beams of electrons can be synchronized to strike the same conductor at the same time, or be out of harmony and synchronization and phase. Multiple electron beams can be used to supply multiple information to the conductors, or to increase the effective beam current without increasing electron beam spot size, by supplying the same information to each beam modulating control grid, when the beams are synchronized.

When a tube of this type is used to control an extermnal smoke-mist pigment, or to form invisible electrostatic images, etc., as described in the three references cited, or in any other manner, the emitted electron beam, when it escapes the end of the conductors 14 and travels across space in the direction of an external accelerating electrode 32, must ionize the air or other gaseous media in the space, and bring the image web 28' or rotating drum surface 59 to ionization potential before an image is formed.

This is not the case in the tubes operated in the Kernkamp U. S. Patent No. 2,291,476, or in Sabbah U. S. Patent No. 2,015,570, or in any of the other tube devices which were invented and designed to be operated in contact with another image receiving media, such as an electro-sensitive recording paper (Teledeltos paper), photographic film, etc. There, an electric circuit of low resistance is completed and the target conductors as in Kernkamp do not have to be designed as escape-points for electrons, nor must any appreciable ionization potential be built up before an image will be formed. But in an image control tube such as herein described where the electrons escape the ends of the conductors and travel through space in the direction of an external acceleration electrodes 32-32', the potential impressed on the conductors 14 by the electron beam 11 must be high enough to ionize the (air) space and the image web, etc, before any electron emission will occur from the exterior ends of the end face conductors, and hence form an image.

50 all image-electrons which escape the external ends of the conductors must first be at the minimum ionization potential of the system (including the (air) space, image web or rotating drum surface, etc.), before any emission will occur.

For a gap in air of 0.001 inch and a good insulating paper as the image web, this ionization potential may be in the order of 600800 volts. One way to overcome this difliculty is to pre-charge the individual conductor as it is swept by the image-signal electron beam, with such pre-charge or bias voltage at or just below the ionization potential of the system. Then, when the cathode ray electron beam contacts a conductor, electrons escape the exterior end of the conductor in direct response to the image signal applied to the modulating control grid of the image electron beam gun. This precharging of each conductor may be done in many ways. One is shown in FIG. 1. FIG, 1 is a cut-away view of the end face of an image control emission tube.

Two of the electron beams from the plurality of electron guns are shown striking the conductors. One is a small cross-section beam 11, and strikes only one end face conductor at a time as it is swept across the tube end face 8. The other beam 23 is of larger cross section, an may strike not only the conductor that is the target of the small-diameter beam, but one on each side of it. Now, the large diameter electron beam 23 is operated at a voltage such as 575 volts, for example, just below the described ionization potential of the space and web system, so that the image-signal target conductor in sequence (and one on each side of it if desired) is raised to a potential just below the ionization potential of the image system (air gap, image web, etc.), The small diameter electron beam 11, which is the image signal beam, can then traverse the gap and web and form electrostatic images, or deposit smoke pigment, etc., depending on the method of operation, without first having to ionize the gap and web system, etc.

The large diameter beam 23 also provides a field to control secondary electrons which might be emitted when the small diameter electron beam 11 strikes the target conductors 14, and prevents them from collecting on the nearby conductors and surface of the glass on insulating end plate 8. This system also eliminates the image beam from having to charge up the target conductors to ionization potential before an image signal will bridge the space as it escapes the exterior end of each conductor.

Another method of pre-charging the end face conductors to slightly less than ionization potential is by positioning an electron emission source, other than a deflected electron beam 11, so that the end face conductors are all charged to the same bia potential at once, but so that the conductors are not interconnected, and are still electrically insulated, so that an image signal fed to one conductor 14 by the small-diameter electron beam 11 will not be emitted by any conductor other than the instantaneous target conductor.

This can be done by positioning a cold cathode or hot cathode emission source spaced from, but extending across, all of the end face conductors.

This electron emission source, although one unit, acts as though each external electron emission conductor is connected to the ionization potential by a diode, which permits electron flow in one direction only; no reverse flow is permitted. If this is a hot cathode emission source, suitable heater connections must be provided as is well known to those versed in the art. Connections to this emission source are not shown in this drawing, in order that it may be more clearly understood; such connections are well known to those versed in the art.

Other types of electron emission sources can be used, internal or external to the tube.

A diode 121' or single-direction fiow rectifier is inserted in the connection to the end face cathode emission source 53, in FIG. 2, to prevent a circuit from being completed from the electron gun to the beam, through the end face grid or emission source 53 back to the high voltage D.C. source 37.

In FIG. 2, the end face control grid 50 is connected to the cathode emission source 53, to simplify the diagram, but it is understood that they can be connected at separate points in the external circuit.

The two external accelerating electrodes 32-32 can be operated at different potentials, depending on the image systems used, pigments, etc., such as 1000 and 1100 volts, for illustration.

An internal bias emission source can be formed on the end plate of the tube.

When a tube such as shown in FIGS. 9, 10, 11, or 15 is used, the electron beams from a multiplicity of guns FIG. 10 can scan the individual rows, or a single electron beam can trace a figure across all of the many layers of conductors, which will then be emitted from the end face of the conductors 14 as shown in FIG. 15. In this case, a multi-layer external accelerating electrode 133, made up of layers of electrodes 32 as shown in FIG. 1 and formed in the same manner as the multi-layer end face of the tube, can be used.

The internal ends of these conductors of the multilayer face plate FIG. 15, can be ground flat, if desired, before operation, or ground to an arc, the center of which is located at the electron gun of the cathode ray tube.

Having described my invention, reference should now be had to the following claims:

I claim: 1. In an electron emission control tube including an evacuated envelope, an electron gun assembly, beam forming and control elements and a deflection system;

the improvement including an electron beam target assembly comprising a substantially monoplanar electrically insulating support plate, and a series of substantially monoplanar non-intersecting electrical conductors affixed in insulated position to said plate, said conductors terminating at the periphery of the support plate in ends adapted to receive and emit electrons; and the peripheral extremities of the emission ends external to the envelope, with a portion of said conductors exposed to the cathode ray electron beam, and substantially perpendicular to the tube axis;

said beam being modulated by an exterior control signal transmitted to the electron gun assembly;

said beam being defiectable for scanning individual conductors in said series to provide selective transmission of electrons through said conductors to the exterior of said tube;

and stationary electrodes spaced laterally from the exterior edges of said support plate parallel to and opposite from the respective ends of said conductors.

2. In the tube of claim 1, each electrode including an insulating plate, and a series of coplanar closely spaced elongated conductors atfixed in insulated position to said electrode plate terminating at their one ends in opposed longitudinal alignment with corresponding conductors in said support plate, the other ends of said electrode conductors being interconnected.

3. In the tube of claim 1, said external ends of each emission conductor being degrees displaced from each other, so that electrons emitted from each end of each conductor are emitted in opposite directions from each other.

4. In the tube of claim 1, and a second electron gun assembly including beam focusing elements to confine its beam to circular cross section for simultaneous impingement upon a conductor, establishing an initial precharge potential in said conductor, the second electron beam being defiectable for transversely scanning said row of conductors throughout its length simultaneous to the scanning of said modulated first electron beam.

5. In the tube of claim 1, a series of such target plate assemblies with said electron emission conductors affixed thereon, positioned in layers in close insulated relation, with a portion of each electron emission conductors on each layer exposed to said electron beam, said layers of target plate assemblies positioned so that the portion of each conductor' on each target assembly layer exposed to said electron beam is substantially perpendicular to the tube axis with the conductor emission ends external to the envelope.

6. In the tube of claim 1, a second support plate upon the interior of said first support plate and of a reduced size to expose portions of the conductors on said first plate, and a second series of coplanar closely space-d elongated conductors afiixed in insulated position to said second plate and lying in a plane parallel to said first conductors, the respective one ends of said second conductors terminating at the outer edge of said second insulating plate on the exterior of the tube, portions of each of said second conductors being exposed to the interior of the tube, so that electrons impressed thereon by said modulated and deflected electron beam escape the exterior one ends of said second conductors to pass through space towards an external accelerating electrode.

7. In the tube of claim 1, additional support plates upon the interior of said first support plate, each succeeding plate being of reduced size, whereby portions of the interior surfaces of said plates are exposed to the interior of the tube, and additional series of coplanar closely spaced elongated conductors atfixed in insulated position upon the interior surface of each of said additional plates respectively, said series of additional conductors lying in planes parallel to the plane of the conductors on said first plate, the respective one ends of said additional conductors terminating at the outer edge of the respective plates on the exterior of the tube, portions of the additional conductors on each of said plates being exposed to the interior of the tube so that electrons impressed thereon by the modulated and deflected electron beam escape the one ends of said additional conductors to pass through space towards external accelerating electrodes.

8. In the tube of claim 1, said support plate being circular, said conductors extending radially inward from its outer edge, and additional flattened insulating plate rings mounted upon each other and upon said circular plate, with the internal diameters of said rings of increasing diameter to expose surface portions of said rings and said plate conductors, and a plurality of coplanar closely spaced radially extending conductors affixed in insulated position upon the exposed rear surface of each ring, the respective one ends of said latter conductors terminating at the outer edges of each ring upon the exterior of said tube, portions of the conductors upon said rings being exposed to the interior of the tube so that electrons impressed on said portions by the modulated and deflected electron beam escape the exterior ends of said ring conductors to pass through space towards external accelerating electrodes.

9. In the tube of claim 8, the interior surface of the tube support plate extending in a direction inclined to a normal to the tube axis, the additional conductors on said rings being similarly inclined.

10. In the tube of claim 1, a second electron gun assembly similiar to said first gun assembly, and including beam-forming and focusing elements to confine its beam to circular cross section for simultaneous impingement upon a conductor, establishing an initial precharge potential in said conductor, said deflection system deflecting the second electron beam for transversely scanning said row of conductors throughout its length simultaneous to the scanning of said modulated first electron beam, with the same external signal simultaneously modulating both electron beams, with both electron beams synchronized to be selectively deflected to the same electron emission conductor at the same time, thereby providing said conductor with double the number of electrons that would be thereby transported by one of said beams, in order to provide an increase in beam current With no increase in diameter of the electron beam as it impinges on said conductor.

11. In the tube of claim 1, a second electron gun assembly similar to said first gun assembly, and including beam-forming and focusing elements to confine its beam to circular cross section for simultaneous impingement upon a conductor, establishing an initial precharge potential in said conductor, said deflection system deflecting the second electron beam for transversely scanning said row. of conductors throughout its length simultaneous to the scanning modulated first electron beam, with two separate external modulating signals individually modulating said two electron beams, with both electron beams synchronized to be selectively deflected to the same electron emission conductor at the same time, thereby superimposing two image signals on the same conductor simultaneously.

12. In the tube of claim 1, a second electron gun assembly similar to said first gun assembly, and including beam-forming and focusing elements to confine its beam to circular cross section for simultaneous impingement upon a conductor, establishing an initial precharge potential in said conductor, said deflection system deflecting the second electron beam for transversely scanning said row of conductors throughout its length simultaneous to the scanning of said modulated first electron beam, with two separate external modulating signals individually modulating said two electron beams, with said beams selectively deflected to electron emission conductors in a predetermined manner.

13. In the tube of claim 1, and a series of said electron emission control tubes arranged in a pair of rows and laterally staggered between rows;

a movable image receiving Web closely spaced from the ends of said tube conductors and reactive to a series of individual image signals transmitted to said tubes for producing on said web a composite 'image;

and corresponding acceleration electrodes on the opposite side of said web respectively spaced from, parallel to, and opposite from the ends of the respective additional series of tube conductors.

14. In the tube of claim 1, and a movable web of image receiving material engaging said electrode on one side thereof and on its other side spaced from said conductor ends, whereby an electrostatic image is formed on the Web in a row corresponding to said series of conductors, and succeeding image rows formed thereon on continued movement on said web, electron discharge means to provide a constant prior precharge on said web, said emission from said tube being adapted to variably counteract said precharge, the variable signal controlled potential from the cathode ray beam in degree neutralizing the effect of the original precharge whereby part of the original precharge remains on the image web forming an invisible electrostatic image.

15. In the tube of claim 1, a continuously rotating drum with its axis in the plane of said conductors, said electrode being on the interior of said drum;

a movable Web spaced between said electrode and the ends of said conductors;

and a confined smoke-pigment of constant density between the ends of said conductors and web, Wh6T by the modulated and deflected electron beam, as it passes through said conductors successively in the direction of said electrode carries particles of pigment to said web for impingement thereon in a permanent manner, to thereby form a row of pigmented elements, and a plurality of such rows on continued movement of said web.

16. In the tube of claim 1, and a moving web of image receiving material positioned between each electrode and said series of conductors so that there is a space between said emission conductors and each image web, whereby electrons passing through said conductors escape the exterior ends thereof and pass through said space towards said accelerating electrodes respectively, imposing an electrostatic charge on the surface of each web to form on said Web a row of such electrostatic charges, and a plurality of such rows of electrostatic charges of said webs upon longitudinal movement thereof past said electrodes, said rows of electrostatic charges defining electrostatic images.

17. In the tube of claim 7, and additional electron gun assemblies spaced from each other and from said first gun assembly, responsive to exterior signals respectively and including deflection systems, so that electrons are impressed on said conductors by modulated and deflected beams from said electron gun assemblies.

18. In combination, an elongated insulating plate;

a series of coplanar elongated conductors affixed in insulation position to said plate;

and a plurality of electron emission control tubes adapted for transmitting electrons to the exterior thereof through a series of insulated conductors, the respective conductors of each tube being in contact respectively with corresponding conductors on said exterior insulating plate, with the electrons emitted from each tube simultaneously transmitted to the respective conductors on said exterior insulating plate.

19. In claim 18, said control tubes being laterally and longitudinally spaced, the conductors of each tube overlying and in contact respectively with corresponding conductors on said insulating plate for transmitting said electrons thereto.

20. In a multiple cathode ray electron emission control tube system for using small tubes to form a large image;

a first row of spaced image pickup tubes lying in a first plane;

a second row of spaced image pickup tubes lying in a second angularly related plane, with the tubes of one row laterally staggered from the tubes of the second row, each tube being arranged to pickup portions of respective image areas of an image source respectively focused upon particular pickup tubes;

a series of cathode ray image control electron emission tubes arranged in a pair of rows and laterally staggered between rows corresponding to said pickup tubes, each emission control tube oonstructioned for transmitting electron beams beyond its end face;

a plurality of spaced elongated conductors Within and extending through said end face parallel to each other and arranged in a row, each tube having an electron gun and modulating grid assembly responsive to the signals transmitted from a corresponding image pickup tube;

a movable image receiving web closely spaced from the electron emission ends of said conductors of said tubes;

electron acceleration electrodes on the opposite side of said web respectively spaced from and parallel to and opposite from the emission ends of respective rows of conductors of said emission control tubes, with said web retaining a series of individual images transmitted to said web retaining a series of individual images transmitted to said web from said tubes, with the image pick up tubes and image emission tubes and the image receiving web all synchronized to as to compositely form on said web a reproduction of the original image.

21. The multiple tube system of claim 20, with the signals from the individual image pickup tubes individually recorded on a magnetic tape, means for transmitting the tape signals to the modulating grid assemblies of corresponding individual cathode ray electron emission control tubes respectively, with the recording of the signals on the tape, and the subsequent transmission of said signals to said individual emission control tubes, and said movable web all synchronized to as to compositely form on said web a reproduction of the original image.

22. A method of controlling the emission of electrons from a series of final electron emission conductors independent of a cathode ray electron emission control tube comprising affixing said final emission conductors to an insulating support surface, retaining said conductors in insulated position to each other and terminating said conductors in ends adapted to emit electrons, positioning an electron accelerating electrode parallel to said emission ends of said electrodes and spaced therefrom, and positioning an electron emission control cathode ray tube, adapted to transmit a predetermined quantity of electrons through its evacuated envelope by means of a series of electron emission conductors, positioned so that said electron emission conductors of said cathode ray tube selectively transport electrons to said exterior final electron emission conductors in response to a selectively deflected and modulated interior cathode ray electron beam, the emission ends respectively of said electron emission conductors of said electron emission conductor aflixed to the exterior insulating support surface independent said cathode ray tube, connecting said electron accelerating electrode so that electrons, emitted from said cathode ray tube to said final exterior electron emission conductors, escape the emission ends of said final emission conductors in the direction of said external accelerating electrode.

23. The method of claim 22, movably positioning a receiving surface between the emission ends of said final emission conductors and said external accelerating electrode, the electrons emitted from said final emission conductors in the direction of said external accelerating electrode imposing an electrostatic charge on the receiving surface, synchronizing the movement of said surface and the deflection and modulation of the cathode ray beam and positioning a multiplicity of such cathode ray electron emission control tubes with their homogeneous electron emission conductors each in contact with a final electron emission conductor, with a greater number of final electron emission conductors affixed to said insulating support surface than are contained in any series of homogeneous electron emission conductors of any individual cathode ray electron emission control tube in contact therewith, said electrons forming one continuous preselected pattern of physical dimensions greater than the size of any series of emission conductors of any individual tube.

24. The method of simultaneously forming two electrostatic images by one cathode ray electron emission control tube, comprising movably positioning a pair of spaced receiving surfaces with a cathode ray emission control tube spaced from the one sides thereof, arranging electron accelerating electrodes upon the other sides of said receiving surfaces, positioning an insulating target face normally to the tube axis, mounting a series of substantially monoplanar conductors on said target face in insulated relation to each other with the respective ends of said conductors terminating at the peripheral edges of said face on the exterior of the tube aligned with said electrodes, applying an exterior signal to the control grid of said tube for modulating the electron beam, and transversely deflecting said beam to successively scan the individual conductors, said beam impinging upon said individual conductors, travelling therethrough in opposite directions outwardly thereof, passing through space in the direction of said electrodes respectively, simultaneously forming an electrostatic image upon each of said receiving surfaces.

25. A method of forming electrostatic images comprising movably positioning a receiving surface, forming a uniformly constant negative charge thereon, positioning a cathode ray electron emission control tube in spaced relation from said side of said receiving surface containing said negative precharge, arranging an electron accelerating electrode on the other side of the receiving surface, continuously counteracting said negative precharge with a positive charge emitted from the emission conductors of said tube, maintaining said positive emission by a positive potential terminating at the electron emission conductors at the one end of the circuit and the acceleration electrode at the other end of the circuit, retaining all emission conductors in insulated position to each other, and modulating a cathode ray beam by a control signal, selectively deflecting said beam to individual emission conductors, with the electrons of said beam variably counteracting the positive emission from said selected conductor, said variably counteracted positive emission variably counteracting the original evenly distributed negative precharge on the movable receiving surface at a spot opposite said selected conductor, controlling said variably deposited positive charge thus imposed by the modulation and deflection of said receiving surface thereto permitting a negative charge in variable amount to remain on said movable receiving surface in a predetermined pattern.

No references cited.

DAVID G. REDINBAUGH, Primary Examiner. H. W. BRITTON, Assistant Examiner. 

1. IN AN ELECTRON EMISSION CONTROL TUBE INCLUDING AN EVACUATED ENVELOPE, AN ELECTRON GUN ASSEMBLY, BEAM FORMING AND CONTROL ELEMENTS AND A DEFLECTION SYSTEM; THE IMPROVEMENT INCLUDING AN ELECTRON BEAM TARGET ASSEMBLY COMPRISING A SUBSTANTIALLY MONOPLANAR ELECTRICALLY INSULATING SUPPORT PLATE, AND A SERIES OF SUBSTANTIALLY MONOPLANAR NON-INTERSECTING ELECTRICAL CONDUCTORS AFFIXED IN INSULATED PORTION TO SAID PLATE, SAID CONDUCTORS TERMINATING AT THE PERIPHERY OF THE SUPPORT PLATE IN ENDS ADAPTED TO RECEIVE AND EMIT ELECTRONS; AND THE PERIPHERAL EXTREMITIES OF THE EMISSION END S EXTERNAL TO THE ENVELOPE, WITH A PORTION OF SAID CONDUCTORS EXPOSED TO THE CATHODE RAY ELECTRON BEAM, AND SUBSTANTIALLY PERPENDICULAR TO THE TUBE AXIS; SAID BEAM BEING MODULATED BY AN EXTERIOR CONTROL SIGNAL TRANSMITTED TO THE ELECTRON GUN ASSEMBLY; SAID BEAM DEFLECTABLE FOR SCANNING INDIVIDUAL CONDUCTORS IN SAID SERIES TO PROVIDE SELECTIVE TRANSMISSION OF ELECTRONS THROUGH SAID CONDUCTORS TO THE EXTERIOR OF SAID TUBE; AND STATIONARY ELECTRODES SPACED LATERALLY FROM THE EXTERIOR EDGES OF SAID SUPPORT PLATE PARALLEL TO AND OPPOSITE FROM THE RESPECTIVE ENDS OF SAID CONDUCTORS.
 18. IN COMBINATION, AN ELONGATED INSULATING PLATE; A SERIES OF COPLANAR ELONGATED CONDUCTORS AFFIXED IN INSULATION POSITION TO SAID PLATE; AND A PLURALITY OF ELECTRON EMISSION CONTROL TUBES ADAPTED FOR TRANSMITTING ELECTRONS TO THE EXTERIOR THEREOF THROUGH A SERIES OF INSULATED CONDUCTORS, THE RESPECTIVE CONDUCTORS OF EACH TUBE BEING IN CONTACT RESPECTIVELY WITH CORRESPONDING CONDUCTORS ON SAID EXTERIOR INSULATING PLATE, WITH THE ELECTRONS EMITTED FROM EACH TUBE SIMULTANEOUSLY TRANSMITTED TO THE RESPECTIVE CONDUCTORS ON SAID EXTERIOR INSULATING PLATE. 